All categories

3 years ago

True or false questions. grade nine science exam.

Biology

1 answer:

Kamila [148]3 years ago

7 0

6.) Sexual reproduction will result in a variety of offspring
7.)sperm smaller than egg
8.)false
9.)true
10.) The plant embryo, sometimes called the seed embryo, is the part of a seed or bud that contains the earliest forms of a plant's roots, stem and leaves. The embryo develops after a fertilized adult plant flowers, and is generally contained within a seed or bud.

Truly hoped this helped

You might be interested in

What is the most common threat to a host organism posed by an invading virus

Ludmilka [50]

Destruction of cells by viral reproduction.

Hope I helped!

7 0

4 years ago

Read 2 more answers

Mendel crossed homozygous tall and short plants. The law of segregation dictates that each sperm of the tall plant randomly pass

Viefleur [7K]

Answer:

D.) If the homozygous tall plant (TT) crosses with a homozygous short plant (tt), then all the F1 plants become heterozygous tall plants (Tt).

Explanation:

Homozygous indicates that the alleles in the genotype are the same. Therefore, the genotype for homozygous tall plants is (TT) and the genotype for homozygous short plants is (tt).

After performing a cross, we know that all of the children will have the heterozygous genotype (Tt).

3 0

2 years ago

7. Pyrethrums are chemicals used to kill insects. In bed bugs, the mutant-type allele, r, confers resistance, but only in homozy

natita [175]

Answer:

Allele frequency

Normal allele $= 0.9$

Mutant r allele $= 0.1$

Genotype frequency

Homozygous normal bugs $= 0.81$

Homozygous mutant bug $= 0.01$

Heterozygous normal bug with one mutant r allele and one normal allele $= 0.18$

Explanation:

It is given that 99% of the bugs were killed after the spray of pyrethrum. This suggests that 1% of the bugs that were not killed must be homozygous for the mutant type allele "r"

Thus, the frequency of homozygous "rr" species i.e $q^2 = 0.01$

From this we can evaluate the frequency of mutant "r" allele.

Thus, $q = \sqrt{0.01} \\$

$q = 0.1$

As per Hardy-Weinberg first equilibrium equation, $p + q = 1$

Substituting the value of q in above equation, we get

$p = 1 - q\\p = 1 - 0.1\\p = 0.9$

Thus, the frequency of homozygous normal bug is equal to

$p^2 = 0.9^2 = 0.81$

As per Hardy-Weinberg second equilibrium equation-

$p^2 + q^2 + 2pq = 1\\$

Substituting all the available values we get -

$0.81 + 0.01+ 2pq = 1\\2pq = 0.18$

Allele frequency

Normal allele $= 0.9$

Mutant r allele $= 0.1$

Genotype frequency

Homozygous normal bugs $= 0.81$

Homozygous mutant bug $= 0.01$

Heterozygous normal bug with one mutant r allele and one normal allele $= 0.18$

3 0

3 years ago

Light touch and gravity are all examples of different environmental

murzikaleks [220]

Different environmental auxins

3 0

4 years ago

A group of educators from a local school district has formed a task force to investigate racial and ethnic identity. Activities

Blizzard [7]

Options for the question have not been provided. They are as follows:

a) if minority group students experience less academic success, they may find themselves in classes with proportionally fewer majority group members.

b) majority group students do not want to interact with minority group students, so they select classes that fewer minority group students will take.

c) gangs in the schools are not integrated.

d) academic success has little to do with the two group interactions.

Answer:

a) if minority group students experience less academic success, they may find themselves in classes with proportionally fewer majority group members.

Explanation:

The educators have decided to open various classes where the majority and the minority group students can interact with each other. However there is a loophole in this plan. A student will choose a class not only on the basis of their liking but also on the basis of their academic level of comfort. Minority group students usually face similar environment and set of problems since they belong to a small close knit minority community and so they might also show similar academic performance.

For example, most of them could be bad in math since their early schooling in their own community could not build a strong foundation for math. As a result they would not perform well in it and will automatically be a part of activity not related to math. Unintentionally they will get clubbed together again in classes and activities with fewer majority group members.

5 0

3 years ago